Missions in space face the problem of spacecrafts being bombarded with space debris including meteoroids ranging in size from microscopic particles to visibly larger compositions. Compounding this problem is the case where the debris is traveling at high velocities.
Some high velocity debris can penetrate a traditional hard shelled spacecraft or cause a great deal of impact damage that weakens the shell of the craft making the shell more susceptible to subsequent failure. In the case of a penetration of the hull, this can lead to loss of a habitable pressurized environment that can endanger a crew. The debris could also impact sensitive equipment in a spacecraft, which could cause a variety of failures.
One solution to this problem has been the application of impact shields disposed about the outer surface of a spacecraft. There are a variety of techniques used including monolithic shielding. Monolithic shielding is typically a hard structure that is designed to prevent the debris from penetrating the shield. These types of shield cover a wide range of materials including metal coverings on the outside of a spacecraft.
Naturally, a solid metal shield—like steel—would be very heavy for a large spacecraft and that translates into a great deal of expense to place such a shield into orbit. This can be particularly true where the spacecraft has a complex geometry.
Carbon nanotubes have a higher strength than steel and yet are lighter. The carbon nanotubes are presently grown in a laboratory environment with the lengths of the tubes being relatively short. What is needed is a spacecraft shield that is comprised of carbon nanotubes of a longer length.